ThreadBoost.h

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///////////////////////////////////////////////////////////////////////////////
//
// File ThreadBoost.h
//
// For more information, please see: http://www.nektar.info
//
// The MIT License
//
// Copyright (c) 2006 Division of Applied Mathematics, Brown University (USA),
// Department of Aeronautics, Imperial College London (UK), and Scientific
// Computing and Imaging Institute, University of Utah (USA).
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the "Software"),
// to deal in the Software without restriction, including without limitation
// the rights to use, copy, modify, merge, publish, distribute, sublicense,
// and/or sell copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
// THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.
//
// Description:
//
///////////////////////////////////////////////////////////////////////////////
 
#ifndef NEKTAR_LIBUTILITIES_THREADBOOST_H_
#define NEKTAR_LIBUTILITIES_THREADBOOST_H_
 
#include "LibUtilities/BasicUtils/Thread.h"
#include <boost/thread/barrier.hpp>
#include <map>
#include <queue>
#include <vector>
 
#include "LibUtilities/Memory/NekMemoryManager.hpp"
 
namespace Nektar
{
namespace Thread
{
 
typedef boost::unique_lock<boost::mutex> Lock;
 
class ThreadWorkerBoost;
 
/**
 * @brief Implementation of ThreadManager using Boost threads.
 */
class ThreadManagerBoost : public ThreadManager
{
    /**
     * So the workers can access the master queue and locks.
     */
    friend class ThreadWorkerBoost;
 
public:
    /// Constructs a ThreadManagerBoost.
    ThreadManagerBoost(unsigned int numWorkers);
    /// Shuts down threading.
    virtual ~ThreadManagerBoost();
    virtual void QueueJobs(std::vector<ThreadJob *> &joblist);
    virtual void QueueJob(ThreadJob *job);
    virtual unsigned int GetNumWorkers();
    virtual unsigned int GetWorkerNum();
    virtual void SetNumWorkers(const unsigned int num);
    virtual void SetNumWorkers();
    virtual unsigned int GetMaxNumWorkers();
    virtual void Wait();
    virtual void SetChunkSize(unsigned int chnk);
    virtual void SetSchedType(SchedType s);
    virtual bool InThread();
    virtual void Hold();
    virtual const std::string &GetType() const;
 
    /// Called by the factory method.
    static ThreadManagerSharedPtr Create(unsigned int numT)
    {
        return std::shared_ptr<ThreadManager>(new ThreadManagerBoost(numT));
    }
 
private:
    ThreadManagerBoost();
    ThreadManagerBoost(const ThreadManagerBoost &);
    bool IsWorking();
    void SetNumWorkersImpl(const unsigned int num);
 
    // Member variables
    const unsigned int m_numThreads;
    unsigned int m_numWorkers;
    std::queue<ThreadJob *> m_masterQueue;
    boost::mutex m_masterQueueMutex;
    boost::mutex m_masterActiveMutex;
    boost::condition_variable m_masterQueueCondVar;
    boost::condition_variable m_masterActiveCondVar;
    ThreadWorkerBoost **m_threadList;
    boost::thread **m_threadThreadList;
    boost::thread::id m_masterThreadId;
    bool *m_threadBusyList;
    bool *m_threadActiveList;
    unsigned int m_chunkSize;
    SchedType m_schedType;
    boost::barrier *m_barrier;
    std::map<boost::thread::id, unsigned int> m_threadMap;
    static std::string className;
    std::string m_type;
};
 
/**
 * @brief Implementation class for ThreadManagerBoost.
 *
 * Each instance of this class corresponds to a worker thread.
 * Instances manage their own queue of jobs to run, grabbing new
 * jobs from the master queue when it is exhausted.
 */
class ThreadWorkerBoost
{
public:
    /// Constructor
    ThreadWorkerBoost(ThreadManagerBoost *threadManager,
                      unsigned int workerNum);
    /// Destructor.
    ~ThreadWorkerBoost();
    /// This provides the interface that boost::thread uses to start the
    /// worker.
    void operator()()
    {
        MainLoop();
    };
    /**
     * @brief Return the index of the worker thread.
     * @return Index of worker thread, an integer between 0 and
     *        (number_of_threads - 1)
     */
    unsigned int GetWorkerNum()
    {
        return m_threadNum;
    };
    /**
     * @brief A signal to shut down.
     *
     * If this method is called the worker will shut down.  Used by the
     * ThreadManagerBoost to stop threading.
     */
    void Stop()
    {
        m_keepgoing = false;
    };
 
private:
    ThreadWorkerBoost();
    ThreadWorkerBoost(const ThreadWorkerBoost &);
    void MainLoop();
    void LoadJobs();
    unsigned int GetNumToLoad();
    void WaitForActive();
    void RunJobs();
 
    // Member variables
    ThreadManagerBoost *m_threadManager;
    std::queue<ThreadJob *> m_workerQueue;
    bool m_keepgoing;
    unsigned int m_threadNum;
};
 
} // namespace Thread
} // namespace Nektar
#endif /* THREADBOOST_H_ */